This isn't "law" but it's accurate today and pretty handy.
#1 is wrong. You can have a complete rifle (no stamp, 16"+) and a short upper. You can not have a complete no stamp lower half and a short upper. Course that's in your home. If you are traveling around with a complete rifle and short upper, then you will have a lot of explaining to do.
And I believe they recently did away with #11. You can no longer shoulder the brace.